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Claudia Nicolay

Bio: Claudia Nicolay is an academic researcher from University of Bonn. The author has contributed to research in topics: Medicine & Internal medicine. The author has an hindex of 11, co-authored 11 publications receiving 746 citations.

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Journal ArticleDOI
TL;DR: Overweight and obese men are more prone to stone formation than overweight women, and the risk of stone formation increased significantly with increasing BMI among both men and women with urolithiasis.
Abstract: Objective: The aim of the study was to assess the influence of overweight and obesity on the risk of calcium oxalate stone formation. Research Methods and Procedures: BMI, 24-hour urine, and serum parameters were evaluated in idiopathic calcium oxalate stone formers (363 men and 164 women) without medical or dietetic pretreatment. Results: Overweight and obesity were present in 59.2% of the men and in 43.9% of the women in the study population. Multiple linear regression analysis revealed a significant positive relationship between BMI and urinary uric acid, sodium, ammonium, and phosphate excretion and an inverse correlation between BMI and urinary pH in both men and women, whereas BMI was associated with urinary oxalate excretion only among women and with urinary calcium excretion only among men. Serum uric acid and creatinine concentrations were correlated with BMI in both genders. Because no association was established between BMI and urinary volume, magnesium, and citrate excretion, inhibitors of calcium oxalate stone formation, the risk of stone formation increased significantly with increasing BMI among both men and women with urolithiasis (p = 0.015). The risk of calcium oxalate stone formation, median number of stone episodes, and frequency of diet-related diseases were highest in overweight and obese men. Discussion: Overweight and obesity are strongly associated with an elevated risk of stone formation in both genders due to an increased urinary excretion of promoters but not inhibitors of calcium oxalate stone formation. Overweight and obese men are more prone to stone formation than overweight women.

255 citations

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TL;DR: Findings suggest that hyperoxaluria predominantly results from increased endogenous production and from intestinal hyperabsorption of oxalate, partly caused by an insufficient supply or low availability of calcium for complexation with oxalates in the intestinal lumen.

138 citations

Journal ArticleDOI
TL;DR: A low fluid intake and an increased intake of protein and alcohol were identified as the most important dietary risk factors and the shift to a nutritionally balanced diet according to the Recommendations significantly reduced the stone forming potential.

117 citations

Journal ArticleDOI
TL;DR: The data shows that in haemophilic patients osteoporosis represents a frequent concomitant observation, and the main cause for reduced bone mass in the ha Hemophiliac is most probably the haemophile arthropathy being typically associated with chronic pain and loss of joint function subsequently leading to inactivity.
Abstract: A relationship between haemophilia and osteoporosis has been suggested, leading to the initiative for a larger study assessing this issue. Bone mineral density (BMD) was measured by osteodensitometry using dual energy X-ray absorptiometry (DEXA) in 62 male patients with severe haemophilia A; mean age 41 +/- 13.1 years, mean body mass index (BMI) 23.5 +/- 3.6 kg m(-2). Using the clinical score suggested by the World Federation of Hemophilia, all patients were assessed to determine the severity of their arthropathy. A reduced BMD defined as osteopenia and osteoporosis by World Health Organization criteria was detected in 27/62 (43.5%) and 16/62 (25.8%) patients, respectively. Fifty-five of sixty-two (88.7%) patients suffered from haemophilic arthropathy. An increased number of affected joints and/or an increased severity were associated with lower BMD in the neck of femur. Pronounced muscle atrophy and loss of joint movement were also associated with low BMD. Furthermore, hepatitis C, low BMI and age were found to be additional risk factors for reduced BMD in the haemophiliac. Our data shows that in haemophilic patients osteoporosis represents a frequent concomitant observation. The main cause for reduced bone mass in the haemophiliac is most probably the haemophilic arthropathy being typically associated with chronic pain and loss of joint function subsequently leading to inactivity. Further studies including control groups are necessary to elucidate the impact of comorbidities such as hepatitis C or HIV on the development of osteoporosis in the haemophiliac.

111 citations

Journal ArticleDOI
TL;DR: The result of statistical calculations showed that the active tactile sensibility of single-tooth implants, both in the anterior and posterior region of the mouth, in combination with a natural opposing tooth is similar to that of pairs of opposing natural teeth, and the implants could be integrated in the stomatognathic control circuit.
Abstract: AIM: The purpose of this randomized split-mouth clinical trial was to determine the active tactile sensibility between single-tooth implants and opposing natural teeth and to compare it with the tactile sensibility of pairs of natural teeth on the contralateral side in the same mouth (intraindividual comparison). MATERIAL AND METHODS: The hypothesis was that the active tactile sensibilities of the implant side and control side are equivalent. Sixty two subjects (n=36 from Bonn, n=26 from Bern) with single-tooth implants (22 anterior and 40 posterior dental implants) were asked to bite on narrow copper foil strips varying in thickness (5-200 microm) and to decide whether or not they were able to identify a foreign body between their teeth. Active tactile sensibility was defined as the 50% threshold of correct answers estimated by means of the Weibull distribution. RESULTS: The results obtained for the interocclusal perception sensibility differed between subjects far more than they differed between natural teeth and implants in the same individual [implant/natural tooth: 16.7+/-11.3 microm (0.6-53.1 microm); natural tooth/natural tooth: 14.3+/-10.6 microm (0.5-68.2 microm)]. The intraindividual differences only amounted to a mean value of 2.4+/-9.4 microm (-15.1 to 27.5 microm). The result of our statistical calculations showed that the active tactile sensibility of single-tooth implants, both in the anterior and posterior region of the mouth, in combination with a natural opposing tooth is similar to that of pairs of opposing natural teeth (double t-test, equivalence margin: +/-8 microm, P 80%). Hence, the implants could be integrated in the stomatognathic control circuit.

44 citations


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TL;DR: These evidence‐based guidelines offer practical recommendations on the diagnosis and general management of hemophilia, as well as the management of complications including musculoskeletal issues, inhibitors, and transfusion‐transmitted infections.
Abstract: Hemophilia is a rare disorder that is complex to diagnose and to manage. These evidence-based guidelines offer practical recommendations on the diagnosis and general management of hemophilia, as well as the management of complications including musculoskeletal issues, inhibitors, and transfusion-transmitted infections. By compiling these guidelines, the World Federation of Hemophilia aims to assist healthcare providers seeking to initiate and/or maintain hemophilia care programs, encourage practice harmonization around the world and, where recommendations lack adequate evidence, stimulate appropriate studies.

1,733 citations

Journal ArticleDOI
26 Jan 2005-JAMA
TL;DR: Obesity and weight gain increase the risk of kidney stone formation, and the magnitude of the increased risk may be greater in women than in men.
Abstract: ContextLarger body size may result in increased urinary excretion of calcium, oxalate, and uric acid, thereby increasing the risk for calcium-containing kidney stones. It is unclear if obesity increases the risk of stone formation, and it is not known if weight gain influences risk.ObjectiveTo determine if weight, weight gain, body mass index (BMI), and waist circumference are associated with kidney stone formation.Design, Setting, and ParticipantsA prospective study of 3 large cohorts: the Health Professionals Follow-up Study (N = 45 988 men; age range at baseline, 40-75 years), the Nurses’ Health Study I (N = 93 758 older women; age range at baseline, 34-59 years), and the Nurses’ Health Study II (N = 101 877 younger women; age range at baseline, 27-44 years).Main Outcome MeasuresIncidence of symptomatic kidney stones.ResultsWe documented 4827 incident kidney stones over a combined 46 years of follow-up. After adjusting for age, dietary factors, fluid intake, and thiazide use, the relative risk (RR) for stone formation in men weighing more than 220 lb (100.0 kg) vs men less than 150 lb (68.2 kg) was 1.44 (95% confidence interval [CI], 1.11-1.86; P = .002 for trend). In older and younger women, RRs for these weight categories were 1.89 (95% CI, 1.52-2.36; P<.001 for trend) and 1.92 (95% CI, 1.59-2.31; P<.001 for trend), respectively. The RR in men who gained more than 35 lb (15.9 kg) since age 21 years vs men whose weight did not change was 1.39 (95% CI, 1.14-1.70; P = .001 for trend). Corresponding RRs for the same categories of weight gain since age 18 years in older and younger women were 1.70 (95% CI, 1.40-2.05; P<.001 for trend) and 1.82 (95% CI, 1.50-2.21; P<.001 for trend). Body mass index was associated with the risk of kidney stone formation: the RR for men with a BMI of 30 or greater vs those with a BMI of 21 to 22.9 was 1.33 (95% CI, 1.08-1.63; P<.001 for trend). Corresponding RRs for the same categories of BMI in older and younger women were 1.90 (95% CI, 1.61-2.25; P<.001 for trend) and 2.09 (95% CI, 1.77-2.48; P<.001 for trend). Waist circumference was also positively associated with risk in men (P = .002 for trend) and in older and younger women (P<.001 for trend for both).ConclusionsObesity and weight gain increase the risk of kidney stone formation. The magnitude of the increased risk may be greater in women than in men.

977 citations

Journal ArticleDOI
TL;DR: The WFH Guidelines for the Management of Hemophilia panelists and co-authors thank the panelists for their time and share their views on how to better understand and treat hemophilia.
Abstract: Alok Srivastava 1 | Elena Santagostino 2 | Alison Dougall 3 | Steve Kitchen 4 | Megan Sutherland 5 | Steven W. Pipe 6 | Manuel Carcao 7 | Johnny Mahlangu 8 | Margaret V. Ragni 9 | Jerzy Windyga 10 | Adolfo Llinás 11 | Nicholas J. Goddard 12 | Richa Mohan 13 | Pradeep M. Poonnoose 14 | Brian M. Feldman 15 | Sandra Zelman Lewis 16 | H. Marijke van den Berg 17 | Glenn F. Pierce 18 | on behalf of the WFH Guidelines for the Management of Hemophilia panelists and co-authors*

751 citations

Journal ArticleDOI
TL;DR: The association between calcium intake and kidney stone formation varies with age and total vitamin C intake seems to increase the risk of symptomatic nephrolithiasis, and dietary recommendations for stone prevention should be tailored to the individual patient.
Abstract: Diet plays an important role in the pathogenesis of kidney stones. Because the metabolism of many dietary factors, such as calcium, may change with age, the relation between diet and kidney stones may be different in older adults. Uncertainty also remains about the association between many dietary factors, such as vitamin C, magnesium, and animal protein, and the risk of kidney stone formation. To examine the association between dietary factors and the risk of incident, symptomatic kidney stones in men and to determine whether these associations vary with age, a prospective cohort study was conducted of 45,619 men without a history of nephrolithiasis. Self-administered food frequency questionnaires were used to assess diet every 4 yr. A total of 1473 incident symptomatic kidney stones were documented during 477,700 person-years of follow-up. For men aged <60 yr, the multivariate relative risk (RR) for stone formation in the highest quintile of dietary calcium as compared with the lowest quintile was 0.69 (95% confidence interval [CI], 0.56 to 0.87; P = 0.01 for trend). By contrast, there was no association between dietary calcium and stone formation in men aged 60 yr or older. The multivariate RR for men who consumed 1000 mg or greater of vitamin C per day compared with those who consumed less than the recommended dietary allowance of 90 mg/d was 1.41 (95% CI, 1.11 to 1.80; P = 0.01 for trend). Other dietary factors showed the following multivariate RR among men in the highest quintile of intake compared with those in the lowest: magnesium, 0.71 (95% CI, 0.56 to 0.89; P = 0.01 for trend); potassium, 0.54 (95% CI, 0.42 to 0.68; P < 0.001 for trend); and fluid, 0.71 (95% CI, 0.59 to 0.85; P < 0.001 for trend). Animal protein was associated with risk only in men with a body mass index <25 kg/m(2) (RR, 1.38; 95% CI, 1.05 to 1.81; P = 0.03 for trend). Sodium, phosphorus, sucrose, phytate, vitamin B(6), vitamin D, and supplemental calcium were not independently associated with risk. In conclusion, the association between calcium intake and kidney stone formation varies with age. Magnesium intake decreases and total vitamin C intake seems to increase the risk of symptomatic nephrolithiasis. Because age and body size affect the relation between diet and kidney stones, dietary recommendations for stone prevention should be tailored to the individual patient.

438 citations

Journal ArticleDOI
TL;DR: Significant differences in frequency of other constituents, particularly uric acid and struvite, reflect eating habits and infection risk factors specific to certain populations, and specific dietary advice is, nowadays, often the most appropriate for prevention and treatment of urolithiasis.
Abstract: Archeological findings give profound evidence that humans have suffered from kidney and bladder stones for centuries. Bladder stones were more prevalent during older ages, but kidney stones became more prevalent during the past 100 years, at least in the more developed countries. Also, treatment options and conservative measures, as well as ‘surgical’ interventions have also been known for a long time. Our current preventive measures are definitively comparable to those of our predecessors. Stone removal, first lithotomy for bladder stones, followed by transurethral methods, was definitively painful and had severe side effects. Then, as now, the incidence of urolithiasis in a given population was dependent on the geographic area, racial distribution, socio-economic status and dietary habits. Changes in the latter factors during the past decades have affected the incidence and also the site and chemical composition of calculi, with calcium oxalate stones being now the most prevalent. Major differences in frequency of other constituents, particularly uric acid and struvite, reflect eating habits and infection risk factors specific to certain populations. Extensive epidemiological observations have emphasized the importance of nutritional factors in the pathogenesis of urolithiasis, and specific dietary advice is, nowadays, often the most appropriate for prevention and treatment of urolithiasis.

354 citations